Mounting for cutter-head knives.



C. F. DRAPER MOUNTING FOR CUTTER HEAD KNIVES. APPLICATlON FILED MAR. 9, 1918.

1,294,638. Patented Feb. 18, 1919.

22 l a 80 EB 4VIJI YIJ-JIIIIIIIIIIIIIIIIII I moewltoz chips klll f6 knife so as to force it CHARLES IE. DRAIPER, OF LANCASTER, PENNSYLVANIA:

MOUNTING FOR CUT'IElZ-I-IEAD KNIVES.

Specification of Letters Patent.

' Patented Feb. is, 1919..

Application filed March 9, 1918. Serial No. 221,522.

To all whom it may concern:

Be it known that I, CHARLES F. DRAPER, a citizen of the United States, residing at Lancaster, in the county of Lancaster and State of Pennsylvania, have invented certain new and useful Improvements in Mounting s for Cutter-Head Knives, of which the following is a specification, reference being had to the accompanying drawi gs.

This invention relates to the cutter heads of planes, jointers, molders, etc., and particularly to the cutting knives and the mounting therefor.

The general object of the invention is to provide an improved knife and mounting for the rotary cutter heads of machines of the character described, so designed that the will not be driven back between the and the head, which often occurs where knives of ordinary form are used.

A further object is whereby a drift may be inserted behind the outward when the knife becomes dull and needs sharpening.

A further object is to provide a construction of this kind comprising a base plate resting on the cutter head and designed to act as a chip break, a cap which is bolted on the cutter head and securely holds the blade in position, and means for holding the knife to the cap so that these parts may be removed as a unit, if necessary.

A further object of this invention is to provide a construction of this kind wherein the cap plate, base plate, and knife may be held together as a unit, and provide means whereby this unit may always be disposed upon the face of a cutter head in accurate position thereon.

Other objects will appear in the course of the following descrlption.

My invention is illustrated in the accompanying drawing, wherein:

Figure 1 is a sectional perspective view of:

a cutter head provided'with myimproved knife mounting; V

Fig. 2 is a section-0n the line 2-2 of Fig. 1;

Fig. 3 is a section on the line 33 of- Fig. 1.

Referring to these drawings, 10 designates the cutter head, which may be of any suitable form and is, of course, rotatablymountblade 13.

' f" s to prov de meansed in the usual manner. A knife and mounting therefor is, of course, disposed on each face of the cutter head. Each mounting for a knife comprises the base plate 11 which rests directly upon the cutter head, and may be formed at its rear end with a rib 12 engaging in a longitudinally extending groove formed in the face of the cutterhead. This plate 11 projects beyond one face of the out ter head and is upwardly and outwardly beveled or ground to a sharp edge. Resting upon this plate 11 is a knife or cutting This knife projects about beyond the plate 11 and has a downwardly and outwardly beveled cutting edge 17 and extends the full length of the cap and plate. The knife is 3 g in thickness and when new is about 1% wide but can be used with my improved mounting until it is worn down to wide.

Disposed above and resting upon the knife 13 is the cap plate 14. The length of these caps will depend upon the length of the head upon which they are to be used, these cap plates extending the full length of the head. Adjacent its rear edge each cap plate is formed upon its under face with a thickened portion 15 having a thickness approximately equal to the thickness of the knife 13 and this thickened portion on its face confronting the plate 11 is formedwith a groove 6 to accommodate the rib or tongue 12 on the plate 11. The knife 13 does not have a depth equal to the depth of the cap plate 14 from its edge to the thickened portion 15 but is only about this depth and passing through the cap plate and into the head are the bolts or screws 18 having relatively large heads resting upon the outer face of the caps. The number of these bolts or screws 18 will depend upon the'length of the cutter head and cap.

It will be noted that the outer edge of the cap is beveled as at 19 and that this bevel is the same as the bevel of the cutting edge of the knife 13 so that the bevel of the knife forms a continuation of the beveled face 19. Preferably the plate 11 will be held at intervals to the cap 14 by means of screws 20 whose heads are disposed in countersunk recesses in the inner face of the plate 11, so that when the bolts 18 are removed, the

plate 11, the knife and the cap 14 may be tions to set the knife out when it becomes with pins 22 which extend dull, so that'it may be re-sharpened.

Preferably the cap plate 14: is provided downward and are insertible through perforations 23 formed in the base plate 11 and into holes 24 drilled in the face of the cutter head. The

- lower portion of each pin 22 where it projects beyond the base plate 11 is reduced slightly in diameter so that it may be readily inserted in these holes 24. By this means the knife mounting may be disposed as a unit upon the cutter head with a certainty and accuracy not secured merely by the use of bolts or screws 18. Thus with my device the mounting, together with the knife 13, may be removed as a whole from the cutter head for shapening or for putting in new knives after they have been cut down to a very small blade and then the mounting be replaced upon the cutter head with the certainty that it will be exactly inthe right position.

Inasmuch as the chip break is a separate I piece from the cutter head, it is obvious that the chipbreak may be made of hard steel, whereas the cutter head is, made of soft steel and-is liable-to wear. The particular form ofca-p plate 14 plays a very important part in connection with the sharpening device forming-the subject matter of my co-pending application, Serial No. 221,523 filed on the 9th day of March, 1918, inasmuch as this sharpening device has a stop which rests upon the beveled face 19 of the cap and has a filc which bears upon the beveled face of the knife-13 so that when required the knife may be filed down so that its beveled face is inexact alinement with the beveledface of the cap plate. Thusthe knives may befiled orsharpened from time to time very, narrow and. yet, will; be, securely by simply inserting drifts through the openings 21, forcing the knives outward to any desired. extent and then filing, them down' so that the beveled face is in the same plane as the beveled face 19. By theprovision of the screws-20, the mounting; as before stated may beheld together as awhole so as toremove-themounting andv sharpen the knives by other means than those disclosed in my co-pending application. With this device the knives maybe worn down: until they are clamped between the brace plate or chip break plate 14 and thus an economy in the life of the knives is secured.

It will be seen that with this cap plate it does not matter how much the knife is forced out beyond the cap plate and beyond the chip break, if the edge of the knife is cut down until the beveled edge of the knife is in the same plane as the beveled face, 19, the knife will have the proper bevel and proper projections and this without regard as to whether the knife is set absolutely parallel with the axis of the cutter head or not.

One of the objects of this invention as will be evident from what has gone before, is to provide means whereby a very thin inexpensive knife may be used. The knives now in use on cutter heads are somewhat over 2; in thickness, whereas-my knife is only in thickness and therefore does not require the amount of steel which is required by the knife now in use on rotary cutter heads and only about the amount of steel used in the cutters of cylindrical heads.

Having described ray invention, what I- claim, 1s:

1. The combination with a cutter head, of a plate resting thereon, projecting beyond the head and having a beveled outer edge, a cap disposed outwardrof the plate, the cap and plate being formed at their rear edges with an inter-engaging tongue and groove, a knife disposed between the cap and the plate, the edge of the knife being disposed at the edge of the plate and the knife and cap having beveled faces disposed in the same plane, and bolts passing through the cap and plate and into the cutter head. and extending behind the inner edge of the-knife.

2. The combination with a cutter head, of a plate resting thereon projecting beyond the head and having an upwardly extending tongue and a beveled outer edge, a cap disposed outward of the plate and having a thickened rear margin formed with a groove receiving said. tongue, a knife disposed between the cap and the plate, the edge of the knife being disposed at the edge of the plate and the knife and cap having beveled faces disposed. in; thesame plane, bolts passing through the cap and plate and into the out ter head and extending behind the inner edge of the knife, and screws passing through the plate and into the cap, the screws having. their head countersunk in the plate.

8. The combination with acutter head, of a plate resting thereon, a cap disposed outward. of the plate, thecap and plate' having beveled; edge face-coinciding in plane with the beveled face of the cap, screws joining be forced out to any desired degree beyond the cap and said plate and disposed behind the beveled face of the cap. 10

the rear edge of the knife, and attaching In testimony whereof I hereunto aflix my screws passing through the cap and the signature in the presence of two wltnesses.

plate and into the cutter head, said screws CHARLES F. DRAPER. being disposed behind the rear edge of the Witnesses:

knife, the cap being formed at intervals WM. H. BROWN,

With a drift opening whereby the knife may A. F. SHENOK.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of I'atents, Washington, D. G. 

